There are quite a lot of types for body thermometers, roughly including mercury thermometers, electronic thermometers, ear thermometers, forehead thermometers and further infrared cameras. While the thermometer types are different, the measurement methods and degrees of recognition thereof are also different accordingly. Mercury thermometers and electronic thermometers belong to contact-typed body thermometers, and have to closely contact human bodies for obtaining correct temperature, wherein the temperatures of main body portions to be measured are rectal temperature, axillary (under arm) temperature and oral temperature. The temperatures measured by direct contact have relatively higher accuracy, but the sensors used thereby have longer response time, and thus cannot be applied in a fever triage station that requires rapid temperature measurements.
Ear thermometers, forehead thermometers and Infrared cameras all belong to non-contact devices, which mainly use Infrared sensors to sense body surface temperature. Although these devices have the advantage of short measurement time, yet the body surface temperatures are varied in accordance with ambient air temperature, so that the values measured thereby need to be adjusted or modified. Although an ear thermometer has relatively higher accuracy, yet it takes some time to replace an ear cover and read temperature, and also there is latent risk with short distance contact while in measurement. In addition, the consummation of ear covers is also quite a waste of resource. Hence, the ear thermometer cannot tackle with the areas having heavy flow of people.
For achieving the goal of heavy-flow and rapid fever triage, only infrared cameras can be relied on. Therefore infrared cameras are installed on many large areas to measure body temperatures for performing fever triage. However, an infrared camera senses the temperature in its whole available area. Therefore, when a testee enters a room from outdoors, his hair, mask or darker clothes will dissipate more heat indoors due to more heat absorbed from sunshine on those parts, causing the infrared camera to make an erroneous fever decision for the testee because of the heat-dissipation problem occurring on those non-human body parts. Generally, the infrared camera needs to be operated in coordination with an observer for monitoring the fever spots, and the measurement process cannot be automatically operated. On the other hand, the observer staring at the screen to artificially exclude erroneous decisions is easily to get tired. Especially in the areas of heavy people flow, since the time for a testee to show up on the screen is quite short and thus the observer is easily to be tired, it is very likely to cause an erroneous decision for allowing a genuine fever patient to pass through.
Hence, there is an urgent need to develop a method and a system for performing fever triage, thereby automatically recognizing fever patients and avoiding making erroneous decisions.